Los Angeles: 'Citizenfour', a documentary on former US intelligence expert Edward Snowden, Sunday night won an Oscar award in the Best Documentary Feature category.

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The movie, helmed by Laura Poitras, Mathilde Bonnefoy and Dirk Wilutzky, narrates how, in 2013, computer analyst Edward Snowden leaked classified documents he had obtained from the National Security Agency, detailing the extent of government surveillance on US citizens.